九丶Web框架之Tornado
概述
Tornado 是 FriendFeed 使用的可擴展的非阻塞式 web 服務器及其相關工具的開源版本。這個 Web 框架看起來有些像web.py 或者 Google 的 webapp，不過爲了能有效利用非阻塞式服務器環境，這個 Web 框架還包含了一些相關的有用工具 和優化。javascript
Tornado 和如今的主流 Web 服務器框架（包括大多數 Python 的框架）有着明顯的區別：它是非阻塞式服務器，並且速度至關快。得利於其 非阻塞的方式和對 epoll 的運用，Tornado 每秒能夠處理數以千計的鏈接，這意味着對於實時 Web 服務來講，Tornado 是一個理想的 Web 框架。咱們開發這個 Web 服務器的主要目的就是爲了處理 FriendFeed 的實時功能 ——在 FriendFeed 的應用裏每個活動用戶都會保持着一個服務器鏈接。（關於如何擴容 服務器，以處理數以千計的客戶端的鏈接的問題，請參閱 C10K problem。）css
下載安裝：html
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pip3 install tornado
源碼安裝
https:
/
/
pypi.python.org
/
packages
/
source
/
t
/
tornado
/
tornado
-
4.3
.tar.gz
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框架使用
1、快速上手java
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#!/usr/bin/env python
# -*- coding:utf-8 -*-
import
tornado.ioloop
import
tornado.web
class
MainHandler(tornado.web.RequestHandler):
def
get(
self
):
self
.write(
"Hello, world"
)
application
=
tornado.web.Application([
(r
"/index"
, MainHandler),
])
if
__name__
=
=
"__main__"
:
application.listen(
8888
)
tornado.ioloop.IOLoop.instance().start()
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執行過程：node
- 第一步：執行腳本，監聽 8888 端口
- 第二步：瀏覽器客戶端訪問 /index --> http://127.0.0.1:8888/index
- 第三步：服務器接受請求，並交由對應的類處理該請求
- 第四步：類接受到請求以後，根據請求方式（post / get / delete ...）的不一樣調用並執行相應的方法
- 第五步：方法返回值的字符串內容發送瀏覽器
#!/usr/bin/env python # -*- coding:utf-8 -*- #!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web from tornado import httpclient from tornado.web import asynchronous from tornado import gen import uimodules as md import uimethods as mt class MainHandler(tornado.web.RequestHandler): @asynchronous @gen.coroutine def get(self): print 'start get ' http = httpclient.AsyncHTTPClient() http.fetch("http://127.0.0.1:8008/post/", self.callback) self.write('end') def callback(self, response): print response.body settings = { 'template_path': 'template', 'static_path': 'static', 'static_url_prefix': '/static/', 'ui_methods': mt, 'ui_modules': md, } application = tornado.web.Application([ (r"/index", MainHandler), ], **settings) if __name__ == "__main__": application.listen(8009) tornado.ioloop.IOLoop.instance().start()
2、路由系統python
路由系統其實就是 url 和 類 的對應關係，這裏不一樣於其餘框架，其餘不少框架均是 url 對應 函數，Tornado中每一個url對應的是一個類。mysql
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#!/usr/bin/env python
# -*- coding:utf-8 -*-
import
tornado.ioloop
import
tornado.web
class
MainHandler(tornado.web.RequestHandler):
def
get(
self
):
self
.write(
"Hello, world"
)
class
StoryHandler(tornado.web.RequestHandler):
def
get(
self
, story_id):
self
.write(
"You requested the story "
+
story_id)
class
BuyHandler(tornado.web.RequestHandler):
def
get(
self
):
self
.write(
"buy.wupeiqi.com/index"
)
application
=
tornado.web.Application([
(r
"/index"
, MainHandler),
(r
"/story/([0-9]+)"
, StoryHandler),
])
application.add_handlers(
'buy.wupeiqi.com$'
, [
(r
'/index'
,BuyHandler),
])
if
__name__
=
=
"__main__"
:
application.listen(
80
)
tornado.ioloop.IOLoop.instance().start()
|
Tornado中原生支持二級域名的路由，如：jquery
3、模板引擎git
Tornao中的模板語言和django中相似，模板引擎將模板文件載入內存，而後將數據嵌入其中，最終獲取到一個完整的字符串，再將字符串返回給請求者。github
Tornado 的模板支持「控制語句」和「表達語句」，控制語句是使用 {% 和 %} 包起來的 例如 {% if len(items) > 2 %}。表達語句是使用 {{ 和 }} 包起來的，例如 {{ items[0] }}。
控制語句和對應的 Python 語句的格式基本徹底相同。咱們支持 if、for、while 和 try，這些語句邏輯結束的位置須要用 {% end %} 作標記。還經過 extends 和 block 語句實現了模板繼承。這些在 template 模塊 的代碼文檔中有着詳細的描述。
注：在使用模板前須要在setting中設置模板路徑："template_path" : "tpl"
一、基本使用
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web class MainHandler(tornado.web.RequestHandler): def get(self): self.render("index.html", list_info = [11,22,33]) application = tornado.web.Application([ (r"/index", MainHandler), ]) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start()
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/> <title>老男孩</title> <link href="{{static_url("css/common.css")}}" rel="stylesheet" /> </head> <body> <div> <ul> {% for item in list_info %} <li>{{item}}</li> {% end %} </ul> </div> <script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script> </body> </html>
在模板中默認提供了一些函數、字段、類以供模板使用：
escape: tornado.escape.xhtml_escape 的別名
xhtml_escape: tornado.escape.xhtml_escape 的別名
url_escape: tornado.escape.url_escape 的別名
json_encode: tornado.escape.json_encode 的別名
squeeze: tornado.escape.squeeze 的別名
linkify: tornado.escape.linkify 的別名
datetime: Python 的 datetime 模組
handler: 當前的 RequestHandler 對象
request: handler.request 的別名
current_user: handler.current_user 的別名
locale: handler.locale 的別名
_: handler.locale.translate 的別名
static_url: for handler.static_url 的別名 xsrf_form_html: handler.xsrf_form_html 的別名
二、母版
<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/> <title>老男孩</title> <link href="{{static_url("css/common.css")}}" rel="stylesheet" /> {% block CSS %}{% end %} </head> <body> <div class="pg-header"> </div> {% block RenderBody %}{% end %} <script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script> {% block JavaScript %}{% end %} </body> </html>
{% extends 'layout.html'%}
{% block CSS %}
<link href="{{static_url("css/index.css")}}" rel="stylesheet" /> {% end %} {% block RenderBody %} <h1>Index</h1> <ul> {% for item in li %} <li>{{item}}</li> {% end %} </ul> {% end %} {% block JavaScript %} {% end %}
三、導入
<div> <ul> <li>1024</li> <li>42區</li> </ul> </div>
<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/> <title>老男孩</title> <link href="{{static_url("css/common.css")}}" rel="stylesheet" /> </head> <body> <div class="pg-header"> {% include 'header.html' %} </div> <script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script> </body> </html>
四、自定義UIMethod以UIModule
a. 定義
# uimethods.py def tab(self): return 'UIMethod'
#!/usr/bin/env python # -*- coding:utf-8 -*- from tornado.web import UIModule from tornado import escape class custom(UIModule): def render(self, *args, **kwargs): return escape.xhtml_escape('<h1>wupeiqi</h1>') #return escape.xhtml_escape('<h1>wupeiqi</h1>')
b. 註冊
#!/usr/bin/env python # -*- coding:utf-8 -*- #!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web from tornado.escape import linkify import uimodules as md import uimethods as mt class MainHandler(tornado.web.RequestHandler): def get(self): self.render('index.html') settings = { 'template_path': 'template', 'static_path': 'static', 'static_url_prefix': '/static/', 'ui_methods': mt, 'ui_modules': md, } application = tornado.web.Application([ (r"/index", MainHandler), ], **settings) if __name__ == "__main__": application.listen(8009) tornado.ioloop.IOLoop.instance().start()
c. 使用
<!DOCTYPE html>
<html>
<head lang="en"> <meta charset="UTF-8"> <title></title> <link href="{{static_url("commons.css")}}" rel="stylesheet" /> </head> <body> <h1>hello</h1> {% module custom(123) %} {{ tab() }} </body>
4、靜態文件
對於靜態文件，能夠配置靜態文件的目錄和前段使用時的前綴，而且Tornaodo還支持靜態文件緩存。
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web class MainHandler(tornado.web.RequestHandler): def get(self): self.render('home/index.html') settings = { 'template_path': 'template', 'static_path': 'static', 'static_url_prefix': '/static/', } application = tornado.web.Application([ (r"/index", MainHandler), ], **settings) if __name__ == "__main__": application.listen(80) tornado.ioloop.IOLoop.instance().start()
<!DOCTYPE html>
<html>
<head lang="en"> <meta charset="UTF-8"> <title></title> <link href="{{static_url("commons.css")}}" rel="stylesheet" /> </head> <body> <h1>hello</h1> </body> </html>
注：靜態文件緩存的實現
def get_content_version(cls, abspath): """Returns a version string for the resource at the given path. This class method may be overridden by subclasses. The default implementation is a hash of the file's contents. .. versionadded:: 3.1 """ data = cls.get_content(abspath) hasher = hashlib.md5() if isinstance(data, bytes): hasher.update(data) else: for chunk in data: hasher.update(chunk) return hasher.hexdigest()
5、cookie
Tornado中能夠對cookie進行操做，而且還能夠對cookie進行簽名以放置僞造。
一、基本操做
class MainHandler(tornado.web.RequestHandler): def get(self): if not self.get_cookie("mycookie"): self.set_cookie("mycookie", "myvalue") self.write("Your cookie was not set yet!") else: self.write("Your cookie was set!")
二、加密cookie（簽名）
Cookie 很容易被惡意的客戶端僞造。加入你想在 cookie 中保存當前登錄用戶的 id 之類的信息，你須要對 cookie 做簽名以防止僞造。Tornado 經過 set_secure_cookie 和 get_secure_cookie 方法直接支持了這種功能。 要使用這些方法，你須要在建立應用時提供一個密鑰，名字爲 cookie_secret。 你能夠把它做爲一個關鍵詞參數傳入應用的設置中：
class MainHandler(tornado.web.RequestHandler): def get(self): if not self.get_secure_cookie("mycookie"): self.set_secure_cookie("mycookie", "myvalue") self.write("Your cookie was not set yet!") else: self.write("Your cookie was set!") application = tornado.web.Application([ (r"/", MainHandler), ], cookie_secret="61oETzKXQAGaYdkL5gEmGeJJFuYh7EQnp2XdTP1o/Vo=")
def _create_signature_v1(secret, *parts): hash = hmac.new(utf8(secret), digestmod=hashlib.sha1) for part in parts: hash.update(utf8(part)) return utf8(hash.hexdigest()) # 加密 def _create_signature_v2(secret, s): hash = hmac.new(utf8(secret), digestmod=hashlib.sha256) hash.update(utf8(s)) return utf8(hash.hexdigest()) def create_signed_value(secret, name, value, version=None, clock=None, key_version=None): if version is None: version = DEFAULT_SIGNED_VALUE_VERSION if clock is None: clock = time.time timestamp = utf8(str(int(clock()))) value = base64.b64encode(utf8(value)) if version == 1: signature = _create_signature_v1(secret, name, value, timestamp) value = b"|".join([value, timestamp, signature]) return value elif version == 2: # The v2 format consists of a version number and a series of # length-prefixed fields "%d:%s", the last of which is a # signature, all separated by pipes. All numbers are in # decimal format with no leading zeros. The signature is an # HMAC-SHA256 of the whole string up to that point, including # the final pipe. # # The fields are: # - format version (i.e. 2; no length prefix) # - key version (integer, default is 0) # - timestamp (integer seconds since epoch) # - name (not encoded; assumed to be ~alphanumeric) # - value (base64-encoded) # - signature (hex-encoded; no length prefix) def format_field(s): return utf8("%d:" % len(s)) + utf8(s) to_sign = b"|".join([ b"2", format_field(str(key_version or 0)), format_field(timestamp), format_field(name), format_field(value), b'']) if isinstance(secret, dict): assert key_version is not None, 'Key version must be set when sign key dict is used' assert version >= 2, 'Version must be at least 2 for key version support' secret = secret[key_version] signature = _create_signature_v2(secret, to_sign) return to_sign + signature else: raise ValueError("Unsupported version %d" % version) # 解密 def _decode_signed_value_v1(secret, name, value, max_age_days, clock): parts = utf8(value).split(b"|") if len(parts) != 3: return None signature = _create_signature_v1(secret, name, parts[0], parts[1]) if not _time_independent_equals(parts[2], signature): gen_log.warning("Invalid cookie signature %r", value) return None timestamp = int(parts[1]) if timestamp < clock() - max_age_days * 86400: gen_log.warning("Expired cookie %r", value) return None if timestamp > clock() + 31 * 86400: # _cookie_signature does not hash a delimiter between the # parts of the cookie, so an attacker could transfer trailing # digits from the payload to the timestamp without altering the # signature. For backwards compatibility, sanity-check timestamp # here instead of modifying _cookie_signature. gen_log.warning("Cookie timestamp in future; possible tampering %r", value) return None if parts[1].startswith(b"0"): gen_log.warning("Tampered cookie %r", value) return None try: return base64.b64decode(parts[0]) except Exception: return None def _decode_fields_v2(value): def _consume_field(s): length, _, rest = s.partition(b':') n = int(length) field_value = rest[:n] # In python 3, indexing bytes returns small integers; we must # use a slice to get a byte string as in python 2. if rest[n:n + 1] != b'|': raise ValueError("malformed v2 signed value field") rest = rest[n + 1:] return field_value, rest rest = value[2:] # remove version number key_version, rest = _consume_field(rest) timestamp, rest = _consume_field(rest) name_field, rest = _consume_field(rest) value_field, passed_sig = _consume_field(rest) return int(key_version), timestamp, name_field, value_field, passed_sig def _decode_signed_value_v2(secret, name, value, max_age_days, clock): try: key_version, timestamp, name_field, value_field, passed_sig = _decode_fields_v2(value) except ValueError: return None signed_string = value[:-len(passed_sig)] if isinstance(secret, dict): try: secret = secret[key_version] except KeyError: return None expected_sig = _create_signature_v2(secret, signed_string) if not _time_independent_equals(passed_sig, expected_sig): return None if name_field != utf8(name): return None timestamp = int(timestamp) if timestamp < clock() - max_age_days * 86400: # The signature has expired.